Why they still rely on search/advertising is well known - Replacing a 150 Billion $$$ source of revenue is not a simple thing.
Its like trying to replace everything ppl do in a midsized rich country with something else.
And compared to Facebook which is still 99% dependent on Ads, Google is much more diversified (total revenue is north of 250 billion). They have cloud, youtube, docs, google play, all the alphabet experiments etc. And most importantly half the worlds online advertising (exchanges/ auctions etc) uses Google ad tech. So Google is not going anywhere.
They just look at the world through a very different lens due to their size. I am guessing they dont see the point of keeping businesses that produce a few hundred million in revenue running, cause they really need businesses that produce a few hundred billion to keep all their free stuff (search, email, chat, chrome, android, video, r&d for other stuff etc) afloat.